Children may suck their thumbs to soothe themselves but this habit can have a bad effect. It could affect proper growth of the mouth and alignment of the teeth.

Sucking is one of the natural reflexes of babies. Infants and young children suck on thumbs, fingers, pacifiers or other objects because it makes them feel secure, happy and helps them learn about their world.

Young children may also suck to soothe themselves. Placing a finger, or thumb, into their mouth provides a sense of security at difficult periods, such as after a scolding or when they are separated from their parents. Since thumb sucking is relaxing, it may induce sleep. For this reason, young children often suck in the evenings or when they are tired.

Problems can result from prolonged thumb sucking

After the permanent teeth come in, sucking may cause problems with the proper growth of the mouth, and alignment of the teeth. It can cause changes in the roof of the mouth.

The intensity of the sucking is a factor which determines whether or not dental problems may result. Children who rest their thumbs passively in their mouths are less likely to have difficulty that those who vigorously suck their thumbs. When the thumb is removed from active thumb suckers, a "popping" sound is often heard.

Some aggressive thumb suckers may have problems with their primary (baby) teeth. If you notice changes in your child's primary teeth, consult your dentist.

When should thumbsucking stop?

Children should have ceased sucking by the time the permanent front teeth are ready to erupt. Usually, children stop between the ages of two and four years. Sucking often gradually lessens during this period, as children spend more of their waking hours exploring their surroundings.

Peer pressure causes many school-aged children to stop. Some studies show that thumb sucking behavior is viewed negatively by classmates. Children with such behaviors may have more problems making friends.

Is sucking a pacifier less harmful?

Pacifiers can affect the teeth essentially the same way as sucking fingers and thumbs. However, it is often an easier habit to break.

How can I help my children break the habit?

Excessive pressure can cause more harm than good.

Keep these tips in mind when helping your children:

• Instead of scolding children for sucking, praise them when they are not.
• Remember that children often suck their thumbs when they feel insecure. Focus on correcting the cause of anxiety, instead of the thumb sucking.
• Children who are sucking for comfort will feel less need for this when their parents provide comfort.
• Reward children when they refrain from sucking during difficult periods, such as when they are separated from their parents.
• Your dentist can encourage children to stop sucking, and explain what could happen to the teeth if they continue.
• If these approaches don't work, remind the children of their habit by bandaging the thumb, or putting a sock on the hand, at night. Your dentist or pediatrician may prescribe a better medication to coat the thumb or use a mouth appliance.